File grub2-efi-chainloader-root.patch of Package grub2

From: Raymund Will <rw@suse.com>
Subject:  Use device part of chainloader target, if present.
References: bnc#871857, bnc#880177
Patch-Mainline: no

Otherwise chainloading is restricted to '$root', which might not even
be readable by EFI!

v1. use grub_file_get_device_name() to get device name

Signed-off-by: Michael Chang <mchang@suse.com>

---
 grub-core/loader/efi/chainloader.c |   17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

Index: grub-2.02~beta2/grub-core/loader/efi/chainloader.c
===================================================================
--- grub-2.02~beta2.orig/grub-core/loader/efi/chainloader.c
+++ grub-2.02~beta2/grub-core/loader/efi/chainloader.c
@@ -706,12 +706,16 @@ grub_cmd_chainloader (grub_command_t cmd
       *(--p16) = 0;
     }
 
+  grub_dprintf ("chain", "cmd='%s'\n", filename);
   file = grub_file_open (filename);
   if (! file)
     goto fail;
 
-  /* Get the root device's device path.  */
-  dev = grub_device_open (0);
+  /* Get the device path from filename. */
+  char *devname = grub_file_get_device_name (filename);
+  dev = grub_device_open (devname);
+  if (devname)
+    grub_free (devname);
   if (! dev)
     goto fail;